Method and device for decoding a received systematic code encoded block

Abstract

A method of decoding a received systematic code encoded block corresponding to an original block of information, wherein the received systematic code encoded block may include soft systematic values, may include detecting an error condition in the received systematic code encoded block. The method may also include decoding the received systematic code encoded block for retrieving the original block of information if the error condition in the received systematic code encoded block is detected and processing the soft systematic values to retrieve the original block of information instead of the decoding if the error condition in the received systematic code encoded block is not detected.

1. A method of decoding a received systematic code encoded block, received from an antenna coupled to an input of a multiplexer, corresponding to an original block of information encoded by a systematic code, the received systematic code encoded block including soft systematic values, the method comprising:
 detecting, using a detector coupled to the antenna, an error condition in the received systematic code encoded block; 
 decoding, using a decoder coupled to a first output of the multiplexer, the received systematic code encoded block for retrieving the original block of information if the error condition in the received systematic code encoded block is detected; and 
 processing, using a first processor coupled to a second output of the multiplexer, the soft systematic values to retrieve the original block of information instead of the decoding if the error condition in the received systematic code encoded block is not detected. 
 
     
     
       2. The method according to  claim 1 , wherein the original block of information comprises bits; and wherein processing the soft systematic values comprises hard decision processing of the soft systematic values to obtain hard decided systematic bits corresponding to the bits of the original block of information. 
     
     
       3. The method according to  claim 1 , wherein the received systematic code encoded block further comprises a soft parity value; and wherein detecting an error condition in the received systematic code encoded block comprises hard decision processing of the soft systematic values to obtain hard decided bits, and performing a parity check of the hard decided bits. 
     
     
       4. The method according to  claim 3 , wherein the error condition in the received systematic code encoded block is detected if a threshold number of parity check errors is exceeded while performing the parity check. 
     
     
       5. The method according to  claim 4 , wherein the received systematic code encoded block has a hamming distance; and wherein the threshold number is equal to half of the hamming distance. 
     
     
       6. The method according to  claim 3 , wherein hard decision processing comprises obtaining hard decided systematic bits from the soft systematic values and first hard decided parity bits from the soft parity values; and wherein performing the parity check comprises encoding the hard decided systematic bits with the systematic code to generate an encoded codeword including parity bits, and detecting an error condition between the first hard decided parity bits and the generated parity bits. 
     
     
       7. The method according to  claim 6 , wherein detecting the error condition between the first hard decided parity bits and the generated parity bits comprises counting a number of the generated parity bits differing from the first hard decided parity bits. 
     
     
       8. The method according to  claim 1  wherein the received systematic code encoded block comprises a low-density parity check code encoded block. 
     
     
       9. A device comprising:
 an antenna configured to receive a systematic code encoded block corresponding to an original block of information encoded by a systematic code, the received systematic code encoded block including soft systematic values; 
 a multiplexer having an input coupled to said antenna and having first and second outputs; 
 a detector coupled to said antenna and configured to detect an error condition in the received systematic code encoded block; 
 a decoder coupled to the first output of said multiplexer and configured to decode the received systematic code encoded block to retrieve the original block of information; 
 a first processor coupled to the second output of said multiplexer and configured to process only the soft systematic values to retrieve the original block of information; and 
 said multiplexer being configured to deliver the received systematic code encoded block to said decoder if the error condition in said received systematic code encoded block is detected and to said first processor instead of said decoder if the error condition in the received systematic code encoded block is not detected. 
 
     
     
       10. The device according to  claim 9 , wherein said original block of information comprises bits, and wherein said first processor comprises a hard decision processor configured to perform hard decision processing of the soft values for obtaining hard decided systematic bits corresponding to the bits of the original block of information. 
     
     
       11. The device according to  claim 9 , wherein the received systematic code encoded block further includes soft parity values; and wherein said detector comprises a second processor configured to perform hard decision processing of the soft values of the received systematic code encoded block to obtain hard decided bits; and further comprising a third processor configured to perform a parity check of the hard decided bits to determine an error condition in the received systematic code encoded block. 
     
     
       12. The device according to  claim 11 , wherein the received systematic encoded block is considered in error if a number of errors resulting from the parity check is greater than a threshold. 
     
     
       13. The device according to  claim 12 , wherein the systematic code encoded block has a minimum hamming distance and the threshold is equal to half of the minimum hamming distance. 
     
     
       14. The device according to  claim 11 , wherein said second processor is configured to deliver hard decided systematic bits from the soft systematic values and first hard decided parity bits from the soft parity values, and said third processor comprises an encoder configured to encode the hard decided systematic bits with the systematic code to generate an encoded codeword including generated parity bits, and an error detector configured to perform an error detection between the first hard decided parity bits and the generated parity bits. 
     
     
       15. The device according to  claim 14 , wherein said error detector comprises a counter configured to count the number of the generated parity bits differing from said first hard decided parity bits. 
     
     
       16. The device according to  claim 9 , wherein the systematic code comprises a low density parity check code. 
     
     
       17. A wireless apparatus comprising:
 a receiving chain comprising
 an antenna configured to receive a systematic code encoded block corresponding to an original block of information, the encoded block including soft systematic values, 
 a multiplexer having an input coupled to said antenna and having first and second outputs, 
 a detector coupled to said antenna to detect whether or not the received encoded block is considered in error, 
 a decoder coupled to the first output of said multiplexer and configured to decode the received encoded block for retrieving the original block of information, 
 a first processor coupled to the second output of said multiplexer and configured to process only the soft systematic values for retrieving the original block of information, and 
 said multiplexer configured to deliver the received systematic code encoded block to said decoder if the error condition in the received systematic code encoded block is detected and to said first processor instead of said decoder if the error condition in the received systematic code encoded block is not detected. 
 
 
     
     
       18. The wireless apparatus according to  claim 17 , further comprising:
 a transmission chain including a systematic code encoder, said transmission chain and said receiving chain operating in a time division mode; 
 said detector comprising a second processor to perform hard decision processing of said soft values and configured to deliver hard decided systematic bits from the soft systematic values and first hard decided parity bits from the soft parity values, and a third processor configured to perform a parity check of the hard decided bits to determine an error condition in the received systematic code encoded block and comprising the systematic code encoder configured to encode the hard decided systematic bits with the systematic code to generate an encoded codeword including generated parity bits, and an error detector configured to perform an error detection between the first hard decided parity bits and the generated parity bits.